coturn-docker

A docker image for a coturn TURN server. See coturn/coturn.

This is the VoIP backend server for a synapse Matrix server. It's optional if you don't plan on enabling VoIP.

The image exposes port 3478. By design, the TURN server will only bind to 127.0.0.1 (the Dockerfile must be altered for this to change).

Building the image

Arguments:

It is generally OK to leave the defaults where they exist.

• COTURN_VERSION (string): a coturn server release name as found at coturn/coturn/releases. Default: 4.5.0.7

• COTURN_USER (string): the name of the system user that will run the coturn server process. This user will be created within the docker container. Default: matrix-coturn

• COTURN_GROUP (string): the name of the user group running the coturn server process. Similarly it will be created within the docker container. Default: matrix-coturn

• SERVER_NAME (string): hostname of the machine which will serve the coturn server. There is no default, hence you must provide a value here. The hostname must be resolvable over the intended network by all potential clients.

Note that a self-signed certificate (10 years validity) with CN=$SERVER_NAME will be created automatically. You should consider replacing with a real one, e.g. Let's Encrypt.

• KEY_NAME (string): name of the private key file that will be auto-generated upon building the docker image. Default: matrix-coturn-key.pem

• CERT_NAME (string): name of the public X.509 certificate file that will be auto-generated upon building the docker image. Default: matrix-coturn-cert.pem

Note: during the build, the script will output something like The automatically generated secret is: <64 char long secret>. This is the automatically generated coturn secret to paste into the synapse server's configuration file if using the coturn server for VoIP support.

Example build command:

This will create an image named image_name for a server url synapse_server_url and it will be tagged latest.

docker build --build-arg SERVER_NAME=<coturn_server_hostname> -t <image_name> .

Running

Exposed volumes:

• /data (certificates mainly, other stuff maybe)

Exposed ports:

• 3478/TCP

Example run command:

docker run -d -v coturn-data:/data -p 3478:3478 <image_name>